You don’t need a power commander, ecu tuning is the way to go.
You’ve spent the money for a full exhaust, make sure you spend the money on a good dyno tune to get the most out of it.
Other things worth noting:
Slip ons don’t dont do much for power as the real restriction is the cat. They sure sound better, and get substantial weight savings.
If you run a power commander, base maps are usually garbage.